Breathing apparatus with cam controlled valve



Un a nt BREATHING APPARATUS WITH CAM CONTROLLED VALVE EinileGagnan, Montreal, Quebec, 'Canada, 'and Jacques Yves Causteau, Monaco, Monaco, assignors to La Spirotechnique i i I jl Application lanuary 31, 1957, Serial N0 637,468 r f The present invention relates to breathing apparatus general and more especially respiratory apparatus for deepsea diving in which abreathable gas, compressed under a high pressure inside a cylinder, is expandedto .a pressure close to that of the ambient mediumbefore the cylinder and this valve is closed whenthe diaphragm is in its equilibrium position, i.e."when the pressure on its two faces are substantially equal. Whentheuser breathes in, the diaphragm is depressed and opens the valve which closes again when the breathing in ceases. Expiration takes place in the ambient medium, through a valve, without goingthrough the expansion chamber of the regulator. Expiration takes place through a different channel from-breathing in. Precautions have to be taken to avoid a spontaneous delivery of air in the ambient medium (particularly in water) when the respective positions of the diaphragm andexhaust point of air give rise to a pressure dilference higher thanthat which operates the regulator. In some apparatus, the remedy consists in bringing back expira- 2,886,033 Patented M 1,

ice

the gas inlet valve at one end and the controllingflexible diaphragm at the other end in axial alignment. The mouthpiece is positioned on the side of the casing be tween the inlet valve and the diaphragm. The controlling diaphragm which has a relatively reduced diameter and increased displacement consists of a first flexible skirt of generally annular formation with the outer periphery se-j cured to the periphery of the one end of the casing and the inner periphery secured tothe periphery of an exhaust valve supporting body of light material, for example,

plastic or thelike. The flexible skirt portion of the'diaphragm lS'ifOldfid on itself between the central exhaust collar.

tion't'o a point close to'the diaphragm, througha special duct, In other appartus, a loading of the expiration valve allows itto open only above a predetenninedpressure difference. In the first case, the 'apparatusis bulky and the complication of the return pipe and the mounting arrangement for the expiration valveincrease its price. In 1y i the second case, the counter-pressure, during expiration, is very important in certain positions and tires the diver,

To overcome these drawba'cks apparatus has been designed wherein thestream of expired gas alone goes through the chamber adjacentthe tdiaphragm, while the i stream ofbreathed in gas goes directly from the gas supply to the mouth-piece 5 without I going i through the chamberf t The United States Patent 2,747,572, Emile Gagnan,

May 29, 1956, shows an improved form ofthis typeof 1 the gasssupplly va1ve.-;-:.In:accordance\withfthe presentin-l 1 t; vention, this is accomplished by providing a casing having ing anexhaust valve 36.

valve supporting body and casing to provide the desired displacement capacity. In a preferred construction the exhaust valve supporting portion of the diaphragm is hollowand formed toprovide a tapering cam body with an annular rim adapted to support the innerperipheral rim of the, flexible skirt of the diaphragm. The cam body includes a central "extension from the apex which is directed inwardly of the casing towards the gas inlet valve and between the upper ends of a plurality of valve actuating levers extending through the casing to a connection with the inlet valve.

The gas inlet valve includes a main stem protruding from the valve box and having an outstandinghead or One endof each of the valve actuating levers engages with the tapered sides of the rigid central diaphragm portion, while the opposite ends are provided with inwardly extending portions which fit beneath the outstanding valve stem head and are loosely retained in this position.

With this arrangement, displacement of the diaphragm inwardly through the inhalations of the user causes the rigid central portion to bear against and spread the upper endsof the levers apart in a cam action which causes a rocking of the opposite ends into contact with the valve stem he-ad and thus opening the valve against the influence of the usual valve closing spring. i

This construction provides a smooth cam action to the valve actuating levers which, as will be appreciated, can be predetermined by the contour of the rigid body of the central diaphragm portion.

Havingthus generally described the nature of the in-' vention,partic'ular reference will be made m the accornpanying drawings wherein there is shown, by way of illustration a preferred embodiment thereof, and in which:

Figure 1 is a sectional view in side elevation of a breathing aparatus embodying the valve controlling means of the invention.

Figure Z .is a trans-axial section of the construction shown in Figure l to illustrate the preferred. arrangement of thevalve actuating levers in more detail. 1

Figure 3fis a partial sectional view corresponding to Figure 1 to illustrate an alternate form of flexible diaphragm and cam body.

I In the embodimentshown, the apparatus consists of a main tubular casing 10, provided at one end with an axial enlargement 12 and on which is mounted by a sleeve; 14, the usual mouthpiece 16. A port 18. is pro-' vided in the casing 10which communicates with the, mouthpiece 16. Preferably casing 10 and sleeve 14 are moulded from suitable plastic material.

Adiaphragm assembly 20is mounted on and masks the enlargement 12 of the casing and consists of a flexible skirt portion 22 and a central rigid cam body 24, support- The flexible skirt portion 22 is secured about the outer periphery to the casing portion 12 by engagement between the peripheral rim 11 of the. portion 12 and the correspondingly shaped rim or flange 25 ofa cover 26. The cover 26 is firmly retained in position on thecasing portion 12 byan annular clamping member 28, which in the construction shown is made of rubber and resiliently expanded to fit over and press tggether the annular flanges 30, 32 of the casing and cover respectively. It will be appreciated that other suitable means might be employed to retain the cover 26 in Pl c f r x mp a p i m v n se u e by suitable nuts and bolts, or the cover .could .be bolted directly-to the casing. The cover 26 as shown is pr o vided with a-plurality of holes 29 which provide .a Communication with ambient medium.

' The flexible diaphragm skirt v 22 is of annularformation with sufficient material intervening the central opening and outer periphery so that it is folded on itself providing the desired displacement characteristics. The inner periphery surrounding the central opening is secured, for example adhesively, to the outer periphery of the rigid supporting body 24 completing the .diaphragm assembly. It is also contemplated .that a substantial :continuationof the skirt 22 might be provided to the lever ends 82 with a spacer 92 mountedon the valve stem over the lever ends 82, the whole being retained by a spring clip or washer 94. The upper ends84 of are of the lever ends 82 against the collar 90 and raises the serve as a support for the exhaust valve .36 or a separate exhaust valve supporting body of annular formation em ployed. In these forms the cam body 24 would be .connected to the exhaust valve supporting members.

f The rigid cam body 24 is preferably shaped, as illustrated, to have a substantially tapered or cone-shaped outer surface .38, with an elongation or stem 39 .extend-. ing axially from the apex of the body. The exhaust valve 36 consists of a flexible disc preferably of rubber mounted axially on the front face .of the body 24 by a central stern 40 retained centrally and for restricted axial movement by an extension 42 of the body 24. a

The end of the casing 10 opposed to the axial enlarge-,

ment 12 is provided with internal threads 50 and a regulating valve assembly 52 is threadably engagedso as .to be retained axially within the casing 10. The valve assembly cated at 62. A further axial boring 64 of reduced diameter connects the recesses 56, .62, and the body 54 is also bored transaxially into and through the recess 61 to provide. gas outlet ports 65, 66. The bottom of the recess 61 surrounding the boring 64 is contoured to provide a valve seat 68. A valve stem 70 having on one end .a

valve closure head 72 is mounted slidably within a cylindrical valve box 74. 3 a The valve and valve box 74 are constructed as a separate assembly which is threadably engagedin the recess- 60 of the body 54 before the entire controlling valve assembly is mounted in the casing 10. The cylindrical valve box 74 is provided with an internal :recess 75 accommodating the valve stem 70 and closure head 72 With the stem 70 extending 'slidably through the .end 76 of the valve box 74. A coil spring 78 is mounted over the valve stem 70 so as to resiliently urge the valve closure head 72 towards the valve seat 68. i A main feature of the present invention resides in'the valve actuating arrangement between the rigid cam: body 7 24 and the valve stem '70. A plurality of lever members 80 are provided each having one end 82formed at substantially right angles with the body of the lever with a groove or recess 83 conforming to the diameter of the valve stem '70 provided in the terminal edge of thebent over end. The other end 84 of each lever is formed :or curved to suit the outside contour of the body 24. a The levers .84, two (2) innthe construction illustrated, are mounted within the casing 10 with the ends 82in contact with the valve stem 70, the recesses 83 fitting about the valve stem. They are retained flexibly in this position by. a flanged collar 90 fitting-overthe valve stem '70 beneath valvestem '70 against the influence of the spring 78. On breathing out, the deflection of thediaphragm assembly in the opposite direction retracts the rigid body 24 relative to the lever ends 84 and therefore, by the spring 78, the stem 70v is moved into valve closing position. The gas exhausted passes through the ports :91 in the body24 and by theresilient action of the exhaust valve 36isdis'; charged into the surrounding medium. [It shouldbe mentioned that the rigid cambody 24 is preferably made of a material having friction-free char acteristics, for example, nylon or the like. Further, while two (2) le'vers are shown by way of illustration, it will be understood that three (3) .or more levers 80 can be utilized and arranged symmetrically about the axis of .the valve setm 70. The elongation or stem 39 of the rigid :body 24 ensures that the rigid body 24 will be always aligned and maintained between the opposed ends of the levers 80 at .the maximum outwardlor exhaust position of the diaphragm assembly. With this arrange -v mer t, it is to be possible by applying a predetermined contour to the rigid body 24 to obtain a smooth even iiit'ingand releasing action to the valve stem 70 and closure head 72 not possible .in the known constructions of this nature.

. t .In. the alternate construction shown in Figure 3 flexiblesliirt portion 22 is replaced by a flexible bellows type portion 122 and the cam body24 is replaced by an alternate cam body 124 which is again of tapered contour but is made as having opposed flat diagonal sides against which the ends 84 of the levers -80 bear. In the construction shown the body 124 is made of a formed strip of suitable material but it will be understood. that it could be moulded in one piece to the desired contour, lIlhewbody 124 is provided with an extension 126 which acts to align the body 124 between the lever ends-84 previously described. The exhaust valve 136 is mounted on an annular supporting member 130 secured to the inner end of the flexible diaphragm portion 122 and the body 124 is secured to the supporting member 130. The

action of this alternate construction is the same aspre: vious y described and it will be appreciated that the diaphragm portion 22 could be combined with the body 124 or the cam body 24 with the diaphragmportion 122 without changing the operation. 5 j I I f-I'hetapering contour of the exterior of therigid bodies 24, 124 acts as a cam and by the appropriate cam surface the degree of motion transmitted by the levers .80 for a proportionate deflecting movement of the .dia: phragm assembly can be predetermined to suit. any (1&2. sired requirement. We claim:

..1. .In a breathing apparatus for divers, in combine-r tion, a closed hollow cylindrical body having at one end a valve box adapted to close the said end of said casing and 1c beconnected to a source of a breathable gasunder pressure, an inlet valve having a valve stem in said valve box for controlling the breathable gas delivered. to said body interior, a diaphragm assembly having .a aflexible portion anda central rigid lbodyvportion mounted on and closing oif the. other end of said hollowbody interiorpa flexible expiration valve mounted .onisaid diaphragm as:

sembly and adapted to discharge outside the gas contained in said hollow body interior when its pressure is greater than the pressure of the medium surrounding said body, a mouthpiece connected to said hollow cylindrical body and a communication port in said body leading to said mouthpiece, said diaphragm assembly central rigid body having a tapering external contour with the apex of said body directed towards and in axial alignment with said inlet valve stem, and at least two lever members extending axially within said cylindrical body with one end of each lever in operative engagement with said valve stem and the other end in frictional engagement with the exterior of said rigid body, whereby deflection of said diaphragm assembly reciprocates said rigid body axially of said cylindrical body and through the tapering conformation of said body a cam action is applied to the ends of said levers in frictional contact therewith, said action being transmitted by the opposite ends of said levers to said valve stem.

2. In a breathing apparatus, as claimed in claim 1, wherein the exterior of said diaphragm assembly central rigid body portion is of conical formation with a stem extending axially from the apex thereof.

3. In a breathing apparatus, as claimed in claim 1, wherein each of said lever ends remote from said diaphragm is bent at substantially right angles from the main body of said lever with the terminal face of said bent lever end recessed to accommodate said valve stem, and there are means mounted on said valve stem adapted to maintain said lever ends in operative contact with said stem.

4. In a breathing apparatus as claimed in claim 1, wherein said diaphragm assembly rigid body is of substantially Y-shaped conformation having opposed flat exterior bearing surfaces converging in the direction of said inlet valve.

5. In a breathing apparatus as claimed in claim 1, wherein said diaphragm assembly flexible portion is a cylindrical bellows of flexible material.

References Cited in the file of this patent UNITED STATES PATENTS Nourse et al Nov. 30, 1954 2,747,572 Gagnan ....v May 29, 1956 

